1. Field of the Invention
The present invention relates to a high-frequency transformer for an inverse-convert welding machine and power supply apparatuses.
2. Description of the Related Art
A conventional high-frequency transformer using cores made of amorphous soft magnetic material is easy to achieve high saturation magnetic flux and permeability. However, this amorphous soft magnetic material is soft and fragile, and very easy to get damaged. In practical application it is often kept in a protection box.
Chinese Utility Model No.942455290.0 disclosed a wing-plate shaped, non-magnetic metal protection box for the ring amorphous soft magnetic material core of a high-frequency transformer. On the external wall of the protection box, outwards-radiated wing-plate heat-sinks were provided, so the heat-dissipation area is increased, and the heat produced due to iron loss will be easier to be radiated out. Thus it overcomes the difficulty of heat dissipation of plastic or of bakelite core-protection box under high frequency condition.
But, since the wing-plate heat-sink is very long, the size of the high-frequency transformer using the core protection box is increased, the wound wire of its winding is lengthened, thus the coupling between high-voltage winding and low-voltage winding is less tight, magnetic leakage of windings and heat loss of windings increase.